Concentration of metalliferous ores



Patented June 14, 1927. I

TUDOR REES SIMPSON, OF-J'OHANNESBURG, TRANSVML, SOUTK'AFRICA, ASSIGNOB r nmnms SEPABATIONINORTE'AMERICAN CORPORATION, or-nnw YORK, n. 2., I

a conromrron.

. concnnrmrron or unrummnous'onns.

' no Drawing. lfpplieatlon filed May-27, 1 9 26, Serial No.112.128, and in the Union of South Africa June This invention comprises improvements in or relating to the concentration of metallif-' erous ores. 7

According to the present invention a prooess of froth-flotation concentration is characterized by effecting flotation'of an aqueous pulp of ore containing metalliferous'matter and gangue in the presence of a protective organic colloid (for example starch, glue, 1o gelatine or the like) the amount of which is sufficient toinhibit flotation of gangue constituents ofthe ore but'insufficient to inhibit flotation of desired metalliferous constituents of the ore.

The present invention relates to the separation of the nietal'lifcrous constituents of ores from gangue minerals of such a nature as to tend to float in substantial quantities under the usualconditions of flotation and which are therefore particularly diflicult to eliminate from concentrates containing the .metalliferous constituents during the operation of flotation processes. The insoluble silicate gangues known .as talcose gangues constitute one type of such gangue minerals. Useful application of the invention'has been found in the-flotation concentration of values from norite rock. Ithas also been found to be highly effective in the flotation of gold ores of the type which is generally known as t-alcose.

The invention has been found to be spe-' cially beneficial in the treatment of ores such as those of the Lydenbur 'district, whic'h carry sulphide minerals an platinum. The colloid may of the ore, during the primary flotation of the one, or during the retreatment of the products of the primary concentration."

' As herein illustrated 'the 'invention comprises the addition of organic protective colloids (for example starch, glue, gelatineor the like) to an aqueous pulp of ore containing an organic sulphhydric. compound such as an alkaline xanthate so that it is present during the flotation with the colloid. In this way. marked improvement in separation ofyalues from gangue maybe secured m some cases. p

The colloid in liquid form may be added before or during the agitation operation. Its effect is apparently more or less to retard the flotation of all the constituents of the ore.

be added during the grindingtraces of sulphhydric It must therefore be added in a regulated I amount, as otherwise not only the "undesired,

but also the desired, constituents may be rendered unfloatable. r

The amount of the colloid employed may be determined experimentally, as is usual w1th the reagents employed in the frothflotation process, and a simple preliminary test will suffice to indicate the proper amount to be used withany particular ore.

The following is one exanrple illustrative of the method ofcarrying the invention into eifect: 1

The ore was a'norite sulphide ore from the Lydenburg district of the Union of South Africa. a It assayed 0.21% of nickel, 0.11% of copper and 2.1 dwts. per ton of platinum group metals. The ore was first crushed so that 95% passed through a screen of meshes per lineal inch and was made into an aqueous pulp having a ratio of water to solids lying between 4 1 and5 1. A preliminary concentration was efl'ected by submitting the pulp to flotation in a sub-aeration machine with the addition of 0.5 lb. of cresol per ton of ore and 0.2 lb. of sodium xanthate per ton 'of (are. The concentrate amounting to aboutone-fifth of the crude ore contained a considerable amount of readily floatable gangue material; it was diluted with water to'form a pulp havin a waterto-s'olid ratio of 10:1 and a stare solution was added at therate of 0.25 lb. of starch per'ton of the original crude ore. Flotation was then effected in a sub-aeration machine without the addition of any other reagent. In the result a concentrate was obtained whichassayed 73.7 dwts. of platinum metals per ton and contained 7.68% ofnickel'and 3.75% of copper. was 89% and the tailings contained only of the the final concentrates was about 2.1%

this example original ore. The gangue in was talcose.

I claim v 1. The process of concentrating a material carrying floatable mineral which consists in agitating a. pulp of the suitably ground material with a mineralfrothing agent in the resence of' an organic compoun and an organic proteetive colloid substance adapted to selec- The recovery of platinum nickel and copper. The amount of and gangue :tively inhibit the flotation of a large propor-.

tion of normally floatable gangue material,

and separating a froth carrying a large pro-- portion of a mineral presen 2. The process of concentrating a material carrying floatable mineral and gangue which consists in agitating a pulp of the suitably ground material with a mineral-frothing agent in the presence of a Xanthate and an organic protective colloid substance adapted to selectively inhibit the flotation of a. large.

proportion of normally floatable gangue ma terial, and separating a froth carrying a large proportion of a mineral present.

3. The process of concentrating a material carrying floatable mineral and gangue which consists in agitating a pulp of the suitably ground material with a mineral-frothing agent in the presence of an organic sulphhydric compound and starch in such proportion as selectively inhibits the flotation of a large proportion of normally floatable gangue material, and separating a froth carv rying a large proportion of a mineral preshibits the flotation of a large proportion of ent.

normally floatable gangue material, and separating a froth carrying-a large proportion of a mineral present.

5. The process of concentrating a material carrying floatable mineral and gangue which consists in agitating a pulp of the suitably ground material with a soluble mineralfrothing agent in the presence ofa Xanthate and with starch in such proportion as selectively inhibits the flotation of a large proportion of normally floatable gangue material, and separating a froth carrying a large proportion of a mineral.'

6. The process of obtaining-a relatively.

,rich concentrate from a mineral-containing material carrying a substantial amount of normally floatable insoluble silicate gangue which consists in agitating a pulp of the suitably ground material with an organic sulphhydric compound and an organic pro- 'tective colloid substance so as to yield. a

froth concentrate relatively rich in a mineral of the material and relatively free from said silicate, and separating the froth concentrate. T

' 7. The process of obtaining a relatively rich concentrate from a mineral-containing material carrying a substantial amount of normally floatable insoluble silicate gangue which consists in agitating a pulp of the suitably groundnnaterial with a xant'hate and an organic protective colloid substance so as to yield a froth concentrate relatively rich in a mineral of; the material and relatively free from said silicate, and separating the frothconcentrate.

8. The processof concentrating ores carrying a substantial amount of normally floatable insoluble silicate gangue which consists in agitating a pulp of the ore with a. mineralfrothing agent so as toyield a mineral-bearing froth carrying a relatively large proportion of a mineral of the ore accompanied by alarge proportion of said silicate, separating the froth, agitating a pulp of the froth concentrate with axanthate and an organic protective colloid substance so as to yield a froth concentrate relatively rich in said mineral and relatively free from said silicate, and separating the froth concentrate.

9. The'process of obtaining a relatively rich concentrate from a mineral-containing, material carrying a substantial amount of normally floatable insoluble silicate gan-gue which consists in agitating a pulp of the suitably ground material with a Xanthate and with a'small proportion of starch so as to yield a froth concentrate relatively rich in a mineral of the ore and-relatively free from said silicate, and separating the froth concentrate.

10. The process of concentrating ores carrying a substantial amount of normally floatable insoluble silicate gangue which consists in agitating a pulp ofthe ore with a mineral-frothing agent and with an organic sulphhydric compound so as to yield a min-- eral-bearing froth carrying a relatively large proportion of a mineral of the ore accompanied by a large proportion of said silicate, separating the froth, agitating a pulp of the. froth concentrate with the further addition of starch so as to yield a froth concentrate relatively rich in said mineral and relatively 1 free from said silicate, and separating the froth concentrate.

; 11. The process of concentrating ores carrying a substantial amount of, normally floatable insoluble silicate gangue which consists in agitating a pulp of the ore with a Inin'eral-frothing agent and with a xanthate soas to yield a mineral-bearing froth carrying a relatively large proportion of a mineral of the ore accompanied by a large pro agitating a pulp of the froth concentrate with the further addition of starch so as to yield a froth concentrate relatively rich in said mineral and relatively free from said portion of said silicate, separating the froth, J

silicate, and separating the froth concen-' trate. p A

12. The process of concentrating a material carrying a floatable mineral and nor-' mally floatable talcose gangue which consists in agitating a pulp of the suitably ground material in 'the presence of a mineral-frothing agent and a xanthate and starch so as the froth? 13. The carrying floatable talcose gangue agitating a pulp of the suitably ground ore mineral-frothing agent to yield a minerai-bearing froth carrying a large proportion of a mineral accompanied by a large proportion in the presence oia and a Kanthate so as recess of concentrating an ore oatable mineral and normally concentrate, agitating the froth concentrate with the further addition of starch so as to which consists in talcose gangue 21 TUDOR REES ield a mineral-hearing froth relatively rich in said mineral and. relatively poor in said lid separating the froth.

In testimony whereof he has signed. his name to this specification at Johannesburg, Transvaal Province of the Union of South 20 day of April 1926.

smrson. 

